Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

289
FXUS63 KLOT 102330
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
630 PM CDT Fri Apr 10 2026

.KEY MESSAGES...

- Warmer, but more active weather pattern with periods of showers
  and storms returns late in the weekend into next week.

- A threat for severe thunderstorms exists Tuesday and
  Wednesday of next week.

&&

.DISCUSSION...
Issued at 250 PM CDT Fri Apr 10 2026

The gloomy, low-hanging stratus and drizzle from this morning
has cleared the area but, in the wake of the departing front, a
thick stratocumulus deck has filled in keeping skies cloudy.
This has kept temperatures a couple of degrees cooler in spots
than previously forecasted. Temperatures this afternoon are
sitting in the upper 40s and lower 50s. Surface high pressure
out to our west will clear up some of this cloud cover before
dusk and lead to a quiet, cool night ahead as it centers itself
overhead late tonight. Early morning lows are forecast in the
middle 30s to near 40 degrees.

This high will scoot off to the east on Saturday making way for
a storm system moving into the northern Plains. We`ll see cloud
cover increase during the day in advance of that system. Most
of our CWA will stay dry for the entire day. Showers are
expected just out to our west during the afternoon. Still being
under the influence of that high with dry low level air in
place, dry conditions are favored through the afternoon, though
can`t rule out a few showers out near the I-39 corridor. During
the evening, the potential translates to north of I-80 for some
showers and a couple of possible embedded thunderstorms. Highs
tomorrow are forecast in the 50s and lower 60s.

Strong warm and moist advection will take place late Saturday
into Sunday between the prominent high to the east and a storm
system to the west spreading a reservoir of high theta-e air
northward across the central CONUS. Early-summer like
temperatures are expected early next week with highs on Sunday
forecast in the middle to upper 70s. The earlier part of Sunday
looks to be dry. Showers and thunderstorms are then expected to
blossom ahead of the storm`s cold front to our west and
progress across our area during the afternoon and evening.
Despite the warm surface temps, relatively warmer air aloft will
great limit instability east of the Mississippi River. So while
storms should not be severe, deep layer saturation and deep
dynamic forcing could stir up some pockets of heavy rainfall.
The surface cold front is progged to get hung up to our
northwest Sunday night as it clings to a developing upstream
cyclone off the lee of the Colorado Rockies.

We`re eyeing the early to middle part of next week for the
potential for severe weather around the region, especially the
Tuesday to Wednesday timeframe for us locally. While that
surface cold front looks to stall upstream from the area late
Sunday, cooler mid-upper level air will spill across the region
behind the departing jet axis Sunday night and, with continued
low level warm advection, promote very steep lapse rates aloft
heading into Monday. With any showers lingering into late Sunday
night or early Monday, it`s possible that a few of them grow
into thunderstorms as instability starts to build around the
area. During the day on Monday, the primary triggers for
convection will remain outside of our CWA with us being locked
in the open warm sector and forecast soundings maintain some BL
CIN throughout the day. Nonetheless, at least isolated instances
of convection will be attainable during the afternoon and
evening, but coverage is highly uncertain. The higher coverage
and more organized severe threat on Monday appears to be to our
west and especially our north across WI where a potent shortwave
will interact with the warm front during the evening. But
forecast soundings would suggest that any storms that develop in
our local area will too have the potential of becoming severe.

Attention then turns to Tuesday and Wednesday where the Storm
Prediction center has highlighted the CWA for potential severe
weather in their days 5 and 6 outlooks. A great deal of
uncertainty looms around this period with disagreements from
medium range guidance on how exactly this system will evolve
across the region. But the idea is that we`ll stay parked in the
storm`s warm sector into Tuesday offering yet more summer-like
temperatures with highs forecast to reach the lower 80s. With
the EML still overhead, high values of BL instability (>2,000
J/kg) are being modeled for Tuesday afternoon. Guidance
generally has convection blossoming nearby during the PM hours
as the low pressure center works into the Midwest. Additional
convection then looks likely on Wednesday as the storm`s cold
front is anticipated to move across. While there looks to be a
slight downtick in instability from Tuesday, a strong effective
shear profile will accompany the front and strong to severe
convection will again be possible with Wednesday`s storms. Will
need to keep a close eye on forecast trends through the weekend
and will refine expectations as more guidance becomes available.

Doom

&&

.AVIATION /00Z TAFS THROUGH 06Z SUNDAY/...
Issued at 630 PM CDT Fri Apr 10 2026

Forecast concerns include...

Wind shift to northeast early this evening.
Chance of showers Saturday evening.

A lake breeze boundary is currently moving inland and will shift
winds to the northeast at the Chicago terminals before
dissipating with sunset. Speeds in the 10-15kt range with some
higher gusts can be expected with its passage. Winds will become
light easterly later this evening which may become light and
variable overnight. East/southeast winds around 10kt are
expected Saturday with some gusts possible in the afternoon.

There is a low chance for patchy fog overnight into early
Saturday morning, especially across northwest IL and at RFD but
confidence is too low for any fog mention with this forecast.

There is a low chance for showers Saturday evening, mainly
across far northern IL with better chances into southern WI.
With uncertainty for the southern edge of this possible
activity, opted to include prob mention in the new 30hr ORD/MDW
forecasts. cms

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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